India has successfully fabricated several kilometres of multifilament Nb-Ti superconductor wire. Helium leak testing of very high order of sensitivity at intermediate stage of fabrication is a pre-requisite for successful fabrication of such wires. Nb-Ti rods are stacked in copper jacket and seal welded by EB welding procedure. Before these billets undergo extrusion, these are helium leak tested by back-pressure techniques to ensure the leak integrity of better than 1 x 10-8 std. cc/sec. of the billets. The paper describes the development of test procedures and presents the important test results data obtained during helium leak testing of several of such billets.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 2, pages 1231 - 1234 Publisher:Ashgate Publishing Company
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